Nisus Writer Express does not support your old Nisus Writer Classic macros.

For safe-keeping, for the possiblity that a future version of Nisus Writer Express will be able to read and use your Classic macros, we suggest you put them:

~/Library/Application Support/Nisus Writer/

Nisus Writer Express macros consist of three types: Menu Command, Perl and AppleScript. For more information choose Nisus Writer Help from the Help menu. Then, in the menu listing click Macros for an overview of what the menu commands do. At the bottom of that page you'll find a link to "More about Nisus Writer Express macros".